Photograph by Juan Manuel Borrero

Like most animals, human beings tend to be reluctant to stand out too far. But some have no choice. Skin pigmentation is one aspect of appearance which has been used throughout history to categorise, exalt or degrade.

In Barcelona zoo, this gorilla stands alone. Despite his magnificent build, it is unlikely that he will reproduce. He is an albino, lacking pigmentation in skin and hair, with weak eyes, and with skin that can be easily damaged by the sun. Albinism puts an animal at a great disadvantage. He will not be attractive as a sexual partner and may even be ostracised by his birth family. Sometimes being taken into captivity or made a pet offers their best chance of survival. Such vulnerability means that albinism tends to be bred out of the genes in the wild. Genetically, albinos are not a good bet.

For domesticated animals, the situation is different. White mice, rats and rabbits are highly prized among pet-fanciers and breeders. Yet even crossing two albinos is not guaranteed to produce albino offspring. The combination of recessive genes that creates albinism is rare: its incidence among all races of human beings is put at one in 17,000. Not rare enough to be freakish, maybe, but uncommon enough to garner stares.

From the inside, pigmentation is less of a problem for albinos than faulty vision, which may range from bad short-sightedness to near-blindness. Despite being described as having red or pink eyes, albino people usually have blue or green eyes filled with light but more than commonly translucent. It is when light shines across them that they assume a pink tinge (like red-eye in flash photography). Think of musicians wearing sunglasses: famous albinos include blues guitarists Johnny and Edgar Winter, who are brothers; Salif Keita, the African musician; and the Rev Archibald Spooner, famous in the 19th century for his comic inversions of words (“spoonerisms”). Perhaps it is no accident that all gained fame through auditory media.

Further back in history, albinism is harder to detect, if we discount fictional characters such as Michael Morpurgo’s albino Maid Marion in his innovative children’s book, Robin of Sherwood, and the timid children Dorothy and Denis inE Nesbit’s 19th-century Bastable stories.

Was Noah an albino? A curious description of him appears in ancient Jewish writings: “His hair was white as snow, and his eyes like the rays of the sun.” Some scholars speculate that Noah might have been affected by albinism. In any event, the US support and study group for the condition is called the National Organization for Albinism and Hypopigmentation, with the acronym Noah.

At least Noah was able to make animals go in two by two, and himself had three sons, one of whom is reputed to have had very dark skin. Not for him the lonely view from the zoo terraces: albinism seems to be one instance where human beings are kinder than animals.

Weblinks www.albinism.org.uk (self-help page for UK albinos); www.nlm.nih.govmedlineplus (encyclopaedia by US government of medical conditions); www.cbc.umn.eduiacnewfacts.htm (explanation of genetics); www.albinism.org (National Organization for Albinism and Hypopigmentation in the USA. Probably the best site).